1. Field of the Invention
The present invention generally relates to a down hole jet pump for production of fluid from a well with the jet pump being powered from a pressure source at the surface and discharging production fluid through production tubing to the surface. The down hole jet pump of this invention is retrievable by reverse flow of fluid down the production tubing to move the jet pump upwardly through the power fluid tubing to the surface. The components of the jet pump are removable and adjustable in the field without the use of special tools thereby enabling the pump to be adjusted to provide optimum operating conditions for each installation and enable interchange and replacement of parts. The down hole jet pump includes passageways for the power fluid, the inlet of production fluid into the throat of the jet pump and for the mixed production fluid and power fluid which is discharged to the production tubing with these passageways being parallel but not concentric in relation to each other thereby enabling the us of larger passageways then if the passageways were concentric thereby providing larger internal clearances which are not as prone to blockage from scale formation, salt, asphalt, sand and similar materials that may be entrained in the production fluid. The lower end of the jet pump assembly may be provided with a structure to remove the ball check valve or foot valve from its seat to enable treating fluid to be pumped down into the formation for treatment of the well.
2. Description of the Prior Art
Various procedures have been developed for delivering oil, gas or water from their normally located underground position to the surface of the earth in order for such fluids to be utilized. Production of underground fluid usually includes the drilling of a well into the formation containing the desired fluids and in some instances, sufficient bottom hole pressure is available to force the production fluids to the surface where it is collected and utilized for commercial purposes. When natural lifting of the well is not sufficient to deliver the production fluids to the surface, a pump is inserted into the well to lift the production fluids. One type of pump used is a reciprocating piston-type pump lowered into the well and operated by a sucker rod extending from the pump to the surface for connection with some type of mechanism to reciprocate the pump. This type of pump is rather costly and requires rather complex operating mechanisms and costly maintenance. There has also been developed a down hole jet pump which has a significant advantage over other pumps since it does not utilize down hole moving parts which reduces the initial cost and maintenance costs by enabling retrieval of the jet pump by reverse flow in the well thereby providing a pump which is more economically feasible from the standpoint of initial cost and maintenance costs. The down hole jet pump of the present invention operates on accepted and well known principles and the following patents disclose related pump structures.
U.S. Pat. No. 823,658 PA0 U.S. Pat. No. 1,161,724 PA0 U.S. Pat. No. 1,782,310 PA0 U.S. Pat. No. 1,992,436 PA0 U.S. Pat. No. 2,080,623 PA0 U.S. Pat. No. 2,080,624 PA0 U.S. Pat. No. 2,468,642 PA0 U.S. Pat. No. 2,869,470 PA0 U.S. Pat. No. 3,216,368 PA0 U.S. Pat. No. 3,367,269 PA0 U.S. Pat. No. 3,551,074 PA0 U.S. Pat. No. 4,135,861 PA0 U.S. Pat. No. 4,171,016 PA0 U.S. Pat. No. 4,183,722 PA0 U.S. Pat. No. 4,285,638 PA0 U.S. Pat. No. 4,293,283 PA0 U.S. Pat. No. 4,504,195 PA0 U.S. Pat. No. 4,658,893 PA0 U.S. Pat. No. 4,664,603
The above prior patents do not disclose the unique features of this invention.